These Forgefix Wing Nuts are a convenient alternative to the standard Hex Nut, and allow hand tightening rather than having to use spanners or other tools. The nuts are bright zinc plated for increased corrosion resistance. Also known as a 'Thumbscrew', the wing nut has two large metal 'wings' for easy tightening and loosening. Zinc coatings prevent oxidation of the protected metal to create a longer lasting finish. It does this by forming a barrier and by acting as a sacrificial anode if this barrier is damaged. Zinc oxide is a fine white dust that (in contrast to iron oxide) does not trigger a breakdown of the substrate’s surface integrity as it is formed. The zinc oxide, if left intact, can act as a barrier to further oxidation, in a way similar to the protection afforded to aluminum and stainless steels by their oxide layers.